This study examines high speed rail (HSR) passengers’ acceptance of mobile ticketing services, as indicated by their mobile access for ticketing information inquiries and use of quick response codes (QR codes) for payment and gate entrance. This study contributes to developing a theoretical framework that brings together mental accounting theory and the technology acceptance model (TAM) to examine consumers’ decision to adopt mobile ticketing. Structural equation modeling was adopted to examine the research hypotheses based on the proposed theoretical framework. The analytical results provide empirical evidence that a combination of the mental accounting theory and TAM is appropriate for explaining passengers’ mobile ticketing service adoption. The findings demonstrate that personal innovativeness has a positive effect on the both mobile access adoption and QR code adoption. Although perceived risk, perceived usefulness, and perceived ease of use all influence QR code adoption, mobile access adoption is not directly affected by perceived risk or perceived ease of use. However, the perceived usefulness associated with such a system has a positive and direct influence on mobile access adoption. Moreover, the findings with respect to the interaction between potential benefit and potential loss of adopting a QR code service show that perceived risk not only directly affects passengers’ mobile ticketing adoption but also offsets the influence of the construct of “perceived usefulness” on passengers’ adoption intention. The conclusions of this study have managerial implications for HSR system operators and may be generalized to the application of mobile ticketing in other transportation industries.